National's leader, John Key, will form a coalition government with the ACT Party and it will hold a clear majority in Parliament.
The results give National 59 seats and ACT 5. United Future leader Peter Dunne adds one seat, making a total of 65.
Labour has 43 seats, the Greens eight, and they are joined by Progressive Party leader Jim Anderton for a total of 52.
The Maori Party holds five of the seven Maori seats but does not hold the balance of power in Parliament.
It is expected to reach a support agreement with National and support the new government on confidence votes.
Miss Clark called Mr Key at 11pm to concede defeat.
New Zealand First did not reach the 5 percent it needed to hold seats in Parliament, and leader Winston Peters' long political career is almost certainly over.
Labour has lost seven of the seats it held in the last Parliament and National has gained 11.